Q&A: Installing 20-Amp Breakers

Q.In a residential rewiring
job, I am removing the existing conductors from steel
flex conduit and installing new #12 solid wire, pulled
through the flex conduit. Can I convert all of the
existing 15-amp breakers to 20-amp breakers?

A.Master electrician Rex
Cauldwell responds: Yes, you can. Since you
have installed 12-gauge wire, and since the
breakers are there to protect the wiring, there is
no reason you can’t install 20-amp
breakers — as long as you don’t
put more than three conductors in the conduit. If
you install more than three conductors in the
conduit, you would have to start to derate the
conductors.